The subject matter disclosed herein relates to methods and systems for self-locking a closure bucket in rotary machines such as turbomachines.
Turbomachines or rotary systems, such as axial compressors and turbines (e.g., gas turbine axial compressors, steam turbines, etc.), may generally include a rotor portion that rotates about an axis during the operation of the system. For example, in an axial compressor or steam turbine, the rotor portion (e.g., disk of a stage) may include a number of buckets (e.g., rotary blades) disposed about a shaft. The buckets are circumferentially disposed adjacent each other about the rotor portion. Often these buckets are loaded onto the rotor portion in a tangential direction. The last bucket loaded on the rotor portion is called the closure bucket. The closure bucket is secured to the rotor portion to lock the buckets in place on the rotor and to block circumferential movement of the buckets along the rotor portion (i.e., relative to the rotor portion). However, the mechanisms used to secure the closure bucket to the rotor portion may result in stress concentration the rotor and/or significant remachining of the rotor during reassembly of the stage (e.g., turbine stage of a steam turbine or compressor stage).